We just swapped a motor in my cousins car.. It had a d15b2 and we swapped the same thing in.. At first the car started to overheat, I thought there might be a crack in the radiator because there was coolant on the ground so it just chilled for a few days because I was too busy to figure it out but a few days later we took it for a test drive and everything seemed fine (no overheating... no nothing) . Then after a few days of driving it all of the sudden it started to overheat... We let it sit for about a 1/2 an hour put some water in it (not much it was almost full) bam drove fine, no overheating... Then again a few days after driving it, it started once again.... Anyone have any Idea what the problem could be..